An apparatus and a method for thermally treating confectionery masses are known from German Patent Application No. DE 35 28 426 A1 corresponding to U.S. Pat. No. 4,724,754 and from German Patent Application No. DE 101 28 287 A1 corresponding to U.S. Patent Application No. 2002/0185011 A1. The known apparatuses include a case housing having a vertical axis and a plurality of parallel tubes being located close to one another. A heating means, especially steam, flows through the tubes. The case housing at its upper end and at its lower end includes a connecting element for connection of a steam conduit and for removal of the condensate, respectively. The confectionery mass is introduced and removed, respectively, by connecting elements being located perpendicular to the axis of the apparatus. The arrangement is chosen such that the confectionery mass flows through the apparatus from below in an upward direction, and the heating medium flows through the apparatus from above in a downward direction.
Dislocating elements being designed as parallel bottoms are located in the interior of the housing in a spaced apart manner, the tubes extending through the bottoms in a sealed fashion. The bottoms include openings in the form of segment-like holes. The holes are located in the edge portions of opposed sides of the inner wall of the case housing. Another embodiment of the known apparatus includes openings being located in the bottoms, the openings being associated with additional baffle plates. In this way, confectionery mass flows about the tubes being located in the inside of the case housing in a direction transverse to the axes of the tubes along a part of the flow path. However, there are other parts which cannot be used to transmit heat and/or in which the flow path extends parallel to the axes of the tubes. In this way, the layer thickness of the confectionery mass located at the tubes is increased. This causes problems especially with temperature sensitive masses which tend to get burned, especially masses containing milk. In addition, the passage cross section through which the confectionery mass flows along the flow path continuously changes in a disadvantageous way such that there will be substantially different velocities of the confectionery mass. This does not only lead to locally different temperatures of the confectionery mass, but also to the danger of the mass being damaged. The residing time of the particles of the confectionery mass in the known apparatus substantially varies since there may be dead zones and nests along the flow path in which parts of the mass reside too long.